The present invention relates generally to the residential construction industry, and more particularly to an improved method of constructing residential buildings wherein the utility intensive rooms of the structure are clustered about and share a common wall with a central utility core or compartment. All piping serving water, sewer, and gas to the various fixtures within the structure extend directly through the common walls of the utility core and are interconnected within the interior of the utility core to form composite water, sewage, and gas piping systems.
In an effort to reduce the rising costs of residential buildings, the construction industry has focused upon improved methods of construction which attempt to minimize the raw material and labor costs of the completed structure. One widely utilized cost reducing construction technique has been the use of concrete slab on grade floors instead of costly raised wood floor and joist structures.
As is well known in the art, prior to pouring such concrete slabs, incoming water and gas lines, and outgoing drain or sewer lines, are emplaced in trenches formed on the site to extend to various room locations within the building. Typically, these lines terminate at "stub-ups" in various locations of the building, which protrude upward, being raised slightly above the final elevation of the concrete slab. The concrete slab is then poured over the water, sewer, and gas lines with the subsequent mudsill/stud framing building techniques usually being utilized to complete the structure. Although such current construction techniques have proven to be more economical than the prior art floor joist/raised sub-floor building techniques, there remains substantial material and labor costs for the trenching and emplacement of the water, sewer, and gas lines upon the site and within the walls of the building. In both small and large floor plan structures alike, the plumbing and gas fixtures which are dictated by room layouts (such as kitchen and bathroom locations) are often separated by significant distances typically ranging up to 50 to 100 feet, thereby requiring substantial trenching and the use of long piping lengths during construction. In addition, these long trenches and piping must be accurately positioned on the site to ensure proper location of the stub-ups in relation to later formed interior and exterior walls of the structure.
Further, the current concrete foundation and floor slab construction method is fraught with substantial time scheduling problems, requiring initial water, sewer, and gas line installation to be completed prior to the pouring of the concrete foundation and floor slab, rough plumbing (i.e., pipe connections within the walls) to occur after wall framing, and finished plumbing (i.e., fixture hook-up) to be completed subsequent to interior wall surfacing and cabinet installation. As such, the water, sewer, and gas system construction personnel have been required to make multiple visits to the construction site at specific times corresponding to the various construction phases of the building. Due to the predominant use of independent contractors for most of these separate construction components (i.e., plumbing, framing, wall surfacing, and cabinetry), construction delays encountered during any one of the separate construction components cause corresponding delays in all of the following construction components, thereby substantially increasing overall construction costs. Additionally, these separate construction components additionally subject the water, sewer, and gas piping systems to a substantial risk of damage with water and sewer stub-ups often being crushed, crimped, or perforated during the subsequent framing process.
In addition, such prior art construction techniques have typically failed to provide any convenient means for modification of the finished water, sewer, and gas piping systems or repair of faulty piping systems emplaced beneath the concrete foundation slab or in the wall of the building. Such failure can permit piping system leakage to remain undetected for a substantial period of time and require costly cutting and tear up of the concrete foundation and/or floor to gain access to the buried piping.
Although these deficiencies have been recognized to a limited extent in the patent art, with some modern building methods providing a clustering of plumbing utilities in a localized area of the building, or portable prefabricated utility units, such as those disclosed in Lankton, U.S. Pat. No. 2,419,319 and U.S. Pat. No. 2,562,050, such attempts still require incoming water and main lines to be buried in a precise location beneath a portion of the floor and additionally severely limit the available floor plan design options of the building. Further, none of these prior art attempts have provided a readily accessible, permanently exposed, common utility area which accommodates repair, subsequent modification, or replacement of the water, sewer, and piping systems. Hence, there exists a substantial need in the art for an improved method of construction which takes advantage of the cost savings associated in concrete slab construction, while minimizing material and labor wastage, reducing construction phase scheduling, eliminating the susceptibility of damage to the water, sewer, and gas piping systems throughout and readily accommodating maintenance repair and modification of the piping systems of the building.